c_project/mysort.c

#include <stddef.h>
#include <stdlib.h>
#include <stdio.h>
#include <fcntl.h>

int counter;

int *resize_array(int *a, size_t new_size)
{
    int *save;
    save = realloc(a, new_size);

    if (save == NULL) {
        fprintf(stderr, "Memory exhuasted\n");
        exit(EXIT_FAILURE);
    }

    return save;
}

void swap(int *a, int *b){
    int old_a = *a;
    *a = *b;
    *b = old_a;
}

int partition(int *array, int left, int right, int pivot){
    int pivot_value = array[pivot];
    swap(&array[pivot], &array[right]);
    int storeIndex = left;
    for(int i = left; i < right; i++){
        if (array[i] < pivot_value){
            swap(&array[i], &array[storeIndex]);
            storeIndex++;
        }
    }

    swap(&array[storeIndex], &array[right]);

    return storeIndex;
}

void quicksort(int *array, int left, int right){
    if (left < right){
        int pivot = right;

        pivot = partition(array, left, right, pivot);
        quicksort(array, left, pivot - 1);
        quicksort(array, pivot + 1, right);
    }
}

int main()
{
    int size = 1;
    int *numbers = malloc(size * sizeof *numbers);
    int *temp = malloc(size * sizeof *temp);
    int error;

    /// Loop through stdin stream grabbing `size` numbers each iteration
    while ((error = fread(temp, sizeof *numbers, 1, stdin))){
        // Should not happen if EOF has been reached or we have loaded all data
        // May happen if we reached EOF at exactly size [didn't find clear documention], in which case next iteration should catch it
        if (error != 0){
            numbers[size - 1] = temp[0];
            size++;
            numbers = resize_array(numbers, size * sizeof *numbers);
        }
    }
    size--;

    quicksort(numbers, 0, size - 1);
    for (int i = 0; i < size; i++){
        printf("%i\n", numbers[i]);
    }

    free(temp);
    free(numbers);
    return 0;
}